LiDAR Controller Unit, Basic Function - GF54.71-P-9892A

Model All (CAR) 

With Code 200 (Conditionally automated driving) 

Overview 

This document contains information on:

• General information 
• Function requirements 
• Function 
  • Lane recognition 
  • Object recognition 
  • Spray mist and precipitation detection 
  • Blockage detection 
  • Determination of detection range 

General information 

LiDAR stands for "Light detection and ranging" and it is a visual measuring method for the spatial location and measurement of distances to objects. The surrounding area is scanned here using IR light beams and mapped in a virtual 3D format as a point cloud. Three-dimensional information about the shape and surface properties is deduced from the surrounding objects that, in particular, are required for conditionally automated driving. For moving objects, the direction of movement can also be determined. This then clearly indicates where an object is moving to. A high degree of safety is achieved in combination with object classification (e.g. pedestrian, lane marking, etc.).

The LiDAR controller unit is located at the front in the center of the radiator shell and basically consists of the following components:

• Infrared laser unit
• Light detector unit
• Motor and mirror unit
• Analysis and control electronics (control unit)
• Heating element for auxiliary heating

The range of the LiDAR sensor is approx. 180 m and the detection range is approx. 120° (horizontal) with an opening angle of approx. 10° (vertical). The laser operates with a wavelength of 905 nm.

Important note:

The LiDAR controller unit uses a Class 1 laser system: If the housing is opened or if it is damaged, laser beams may damage the retina.

Function requirements 

• Calibration procedure completed successfully
• Blockage not detected

Function 

The LiDAR controller unit sends pulsed infrared light pulses through two rotating mirrors, which are then reflected by objects (e.g. road users, obstacles or lane markings). The receiver detects the reflected pulses and uses them to determine the position of the target object through calculation of the laser pulse duration. The controller unit then creates a 3D map of the area in front of your own vehicle. Vehicle dynamics signals (wheel speed, steering angle, lateral acceleration and longitudinal acceleration, etc.) are also used to determine the movement of the vehicle.

The following functions are also implemented in the evaluation and control electronics of the LiDAR controller unit:

Lane recognition 

The lane markings and their course are recognized on both sides of its own lane.

Object recognition 

Both motionless and moving objects in the field of view are detected.

Spray mist and precipitation detection 

Vehicles driving in front in the sensor's field of view that form salt spray or any precipitation or snow that restricts the sensor's detection range are detected here.

Blockage detection 

Any opacity on the front side of the sensor (e.g. due to dirt) that impairs object recognition and lane recognition performance is detected here.

Determination of detection range 

The possible detection range in which a reference target can be detected is determined.

The LiDAR controller unit also heats or cleans the front side of the sensor to reduce the effects of dirt, ice or snow. A self-monitoring function is run through at the start or cyclically during operation. The heating element is located as a vapor deposited heater wire on the front side and prevents any fogging of the optics. For cleaning purposes, a telescopic nozzle located above the sensor is supplied with washer fluid by the LiDAR cleaning system pump. The telescopic nozzle and the spray nozzle are heated.

The LiDAR controller unit is connected to the vehicle's network architecture through Ethernet.

The following information and requests are mainly sent to the driver assistance systems control unit:

• Information:
  • Lane data
  • Object data (object size, object type, object direction of motion, distance)
  • Weather conditions
  • System status (including diagnosis information)
• Requests:
  • LiDAR cleaning system pump
  • Warning and information messages

Function restrictions: 

• Curvatures with a radius of < 150 m.
• Lane width > 4.20 m.
• Dazzle through very low sun in the immediate detection range.
• Heavily soiled, scratched or damaged cover panel.

	Component part descriptions
	LiDAR controller unit, component description	Model 223 with code 200 (Conditionally automated driving)	GF54.71-P-9893A
		Model 297 with code 200 (Conditionally automated driving)	GF54.71-P-9893D
	Spray nozzle heater, component description	Model 223	GF82.35-P-5002A
		Model 297	GF82.35-P-5002D
	Spray nozzle hose heater component description	Model 223	GF82.35-P-5003A
		Model 297	GF82.35-P-5003D